Imaging systems having broadband monochromatic and chromatic image sensors

An imaging device may have a monochrome image sensor and a bi-chromatic image sensor. A beam splitter may split incident light between the two image sensors. The monochrome image sensor may have an array of broadband image sensor pixels that generate broadband image signals. The bi-chromatic image sensor may have an array of red and blue image pixels that generate red and blue image signals. The image sensors may be coupled to processing circuitry that performs processing operations on only the broadband image signals to produce monochrome images, or on the red, blue, and broadband image signals to produce color images. Processing operations used to produce color images may include chroma-demosaicking and/or point filter operations.